In a large number of industrial installations, especially in the nuclear and chemical industries, there currently exist pipes conveying liquids containing sludge and solid particles. The latter create deposits on the walls of the pipes and frequently result in the formation of plugs.
Currently, various solutions are available to unclog blocked up pipes.
One first known solution consists of successively injecting acid into the pipe and then welding it so as to dissolve the plug. This method, which mainly concerns porous or incompletely sealed plugs, has the drawback of being long and does not always provide the desired results.
Another known unclogging method consists of pressurizing the plugged portion of the pipe by connecting the latter directly onto the discharge orifice of a pressure test pump. This technique, simple to implement, does have the drawback of having to pressurize the pipe, this often having the effect of compressing the plug and renders its unclogging by the other existing methods being virtually impossible. Moreover, the pressure rise of the circuit may result in the liquid ascending at the moment of decompression, this possibly having dangerous consequences.
A third technique similar to the latter method consists of sending vapor under controlled pressure into the clogged pipe. This technique has virtually the same drawbacks as the preceding method and consists of using a pressure test pump.
A further known method easy to implement consists of introducing into the clogged up pipe a metallic steel flexible pipe known as a mechanical shuttle. However, this method has the drawback of resulting in the pipe possibly being damaged. In addition, the removal of the flexible pipe is delicate when the operation is carried out in a highly irradiating circuit.
Finally, a final known technique described in the document FR-A-2 611 540 consists of applying a low-frequency excitation to the liquid column contained in the pipe. This method, which has numerous advantages, does, however, have the drawback of pressurizing the circuit and results in a slight excitation of the pipes.